A diver jumps into the pond at the Underwater Explosions and Surface Testing site at Aberdeen Proving Ground to conduct a surface supply dive scenario the afternoon of June 2, 2011.

A diver jumps into the pond at the Underwater Explosions and Surface Testing site at Aberdeen Proving Ground to conduct a surface supply dive scenario the afternoon of June 2, 2011. (U.S. Army photo by Sgt. 1st Class Kelly Jo Bridgwater)

Chip Chase, left, is president of Poseidon International, a company that does diving, engineering and consulting work. He retired from the Navy after 35 years and retired as a commander of a reserve attachment of Mobile Diving and Salvage Unit also based in Little Creek, Va. Also in the picture...

Chip Chase, left, is president of Poseidon International, a company that does diving, engineering and consulting work. He retired from the Navy after 35 years and retired as a commander of a reserve attachment of Mobile Diving and Salvage Unit also based in Little Creek, Va. Also in the picture... (Handout photo courtesy of Chip Chase)

Officials at the Army base in Harford County released few details late Tuesday about the incident, which occurred about 2:30 p.m. at the Unexploded Ordnance Range pond. The man-made body of water is also known as the Super Pond.

A Navy spokesman said the families of the sailors had been notified, but officials were withholding their names for 24 hours in accordance with Navy policy. Lt. Nathan C. Potter, the spokesman said the victims were in the Mobile Diving and Salvage Unit.

Base rescue workers called to the Super Pond arrived to find one of the individuals dead, base spokesman Kelly Luster said. The other was taken to a local medical facility and pronounced dead.

A Harford County emergency response source said the divers were in cardiac arrest when they surfaced and had been working in the pond on air hoses, not self-contained breathing units, and were tethered to each other.

The two divers were from Joint Base Little Creek-Fort Story in Virginia Beach, Va., the Associated Press reported.

The incident came less than a month after the death of a diver at the Super Pond.

George H. Lazzaro Jr., an engineering technician in the Firepower Directorate of the Aberdeen Test Center, died Jan. 30 while doing routine maintenance on the test infrastructure.

Lazzaro, 41, lived in Nottingham. Luster said Tuesday that his death remains under investigation. He said the death last month and the two deaths Tuesday were not related.

The Underwater Test Facility, better known as the Super Pond, is a 1,070-foot-long, 150-foot-deep pond carved out of the bank of the Bush River to allow the Army to conduct shock tests of ships, boats and submarines for the Defense Department, academic researchers and private businesses.

No area dive teams were called to the base on Tuesday to assist in any rescue or recovery operations, Harford emergency officials said. The volunteer Aberdeen Fire Department did, however, send a unit to the installation to provide backup for the proving ground fire department.

An aerial view supplied by the Army of Aberdeen Proving Ground's UNDEX Testing Facility, commonly known as the "Super Pond," where two divers died Tuesday, the Army said. Another diver died on Jan. 30.

The Maryland State Department of Education has selected the Biomedical Sciences Program at Bel Air High School to receive the 2015 Career and Technology Education Outstanding Secondary CTE Program of Excellence, Harford County Public Schools announced Monday.